US 9,810,315 B1
Vehicle and system of controlling a vehicle transmission
Bradley Ronald Heuver, South Lyon, MI (US)
Assigned to Ford Global Technologies, LLC, Dearborn, MI (US)
Filed by FORD GLOBAL TECHNOLOGIES, LLC, Dearborn, MI (US)
Filed on Jul. 14, 2016, as Appl. No. 15/210,466.
Int. Cl. F16H 61/00 (2006.01); F16H 61/02 (2006.01); F15B 1/02 (2006.01)
CPC F16H 61/0021 (2013.01) [F15B 1/024 (2013.01); F16H 61/0206 (2013.01); F16H 2061/0034 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A transmission comprising:
a high pressure fluid circuit that supplies fluid to actuate clutches;
a low pressure fluid circuit that supplies fluid to clutch pressure balance chambers;
a pump configured to supply fluid to the high and low pressure fluid circuits;
a fluid accumulator;
an output shaft; and
a controller programmed to,
in response to fluid demand exceeding a capacity of the pump, isolate the low pressure circuit from the pump to prevent starving the high pressure fluid circuit,
in response to a speed of the output shaft exceeding a threshold while the low the pressure circuit is isolated from the pump, discharge the accumulator into the high pressure circuit, and
in response to fluid demand decreasing to less than the capacity of the pump, reconnect the low pressure circuit to the pump.